Synthesis of magnetic biochar for utilization in Fenton based - - PowerPoint PPT Presentation

Synthesis of magnetic biochar for utilization in Fenton based process

Gozde Duman T ac, Jale Yanik Ege University, Faculty of Science, Chemistry Department,Izmir/ TURKEY

Dye wastewater treatment

Dye wastewat er treatmen t

Coagulatio n Adsorption Fenton Reaction O3

• xidation

Membrane separation

• Used in the textile, cosmetic, pharmaceutical

and food industries

• High volumes of wastewater during operation
• Complex structure, resistant to biodegradation

Based on chemical oxidation by forming very reactive species such as hydroxyl radicals (·OH) Degrades organic pollutants completely to harmless chemicals, mainly CO2 and H2O Feasible option for biologically persistent wastewater Widely recognized as highly effjcient treatments for recalcitrant wastewater

Advanced Oxidation Process

The chemical oxidation of organic compounds by H2O2 using Fe ions as a catalyst Particularly attractive because of

• the low costs
• the lack of toxicity of the reagents
• the simplicity of the technology
• Fenton Process

Disadvantages of homogeneous catalysis

• 50–80ppm of ions needed in solution
• above environmental regulations to dump directly into the

environment => [Fe]max =2 ppm

• the removal/treatment of the sludge-containing metal ions at the

end of treatment

• Not recyclable

Fenton Process

Fe

3+

Fe

3+

Fe

2+

Fe

2+

Dis s

• lution

Fe

3+(a q)

H

2O 2

Dis s

• lution

Fe

2+(a q)

H

2O 2

Fe

3+

+OH

• +HO

H

2O 2

Fe

2+

+H

+

+HO

2

H

+

+HO

2/O 2

H

2O 2

Fe

3+

+OH

• +HO

C a ta ly s t

Heterogeneous catalyst Pure Metal oxides; poor stability, inert activity, etc.

Biochar

Biochar for wastewater treatment

• Adsorbent
• support for oxidation catalyst

Biochar

Modifjcation/activation

M M M M COOH HO O- OR OH

Biochar Increase surface area Surface functional group Loading metal species Biomass Hydrothermal Carbonization Pyrolysis

PURPOSE

Decolorization of wastewater containing methylene blue via Fenton process in presence of Fe doped biochar

 Synthesis and characterization of Fe loaded biochars  Catalyst screening  Parametric study on Methylene blue removal Fe doped biocha r

ANAL YSIS

Performed by measuring the absorbance of the methylene blue concentration at the maximum absorbance wavelength of each compound in a UV/VIS Spectrophotometer ( Varian Cary 100 Bio)  The wavelengths λ =664 nm for MB, Removal effjciency (de-colorization) was calculated by MB Removal where m0 and mf were initial and fjnal concentration of MB

termination of Methylene blue (MB) removal

MATERIALS AND METHODS

Biomass: T wo phase olive mill waste(TP)

TPOMW

Moisture 66.4 Proximate analysis, wt % (db) Ash 3.8 Volatile matter 68.5 Fixed carbon 27.7

Ultimate analysis, wt % (db)

C 51.47 H 7.02 N 1.09 S 0.13 O 36.51

Properties of TPOMW, % Fe source:

• FeSO4(Fe),
• Red Mud (RM): Fe rich ( containing

38% Fe2O3) waste sludge from aluminum company

• Acidifjed Red Mud (ARM): Dissolved in

10 % HCl solution

MATERIALS AND METHODS

TPdry+ Fe source in solution

*Magnetic properties*

Process Yield**, % P-Fe-500* Pyrolysis 60.2 P-Fe-700* Pyrolysis 55.7 HTC-Fe HTC 49.6 P-RM-500* Pyrolysis 68.9 P-RM-700* Pyrolysis 57.2 HTC-RM HTC 81.7 P-ARM-500* Pyrolysis 72.0 P-ARM-700* Pyrolysis 61.3 Pyrolysis at 500 and 700 oC for 1 hour Hydrothermal carbonization (HTC) at 220 oC for 1 hour Impregnation in oven at 110 oC overnight Filtrated,washed and dried in oven at 110 oC overnight

Thermocouple

Oven

Oven

**based on initial biomass amount

MATERIALS AND METHODS

Fenton Reaction Experiments

Batch experiments

• 250 ml erlenmayer fmask
• 150 rpm shaking

Tested parameters

• Catalyst type
• Day light and under dark
• Concentration of H2O2
• pH
• MB concentration

RESUL TS-Comparison of Fe source

1 2 3 4 5 10 20 30 40 50 60 70 80 90 100

P-Fe-500 P-Fe-700

Time (hour) MB Removal ( %)

Conditions: 100 ppm MB, 10 mM H2O2, daylight, 150 rpm shaker, pH was adjusted to 3

• RM based biochars had low

activity.

• The use of ARM instead of

RM improved the removal

• f MB.
• Pyrolysis temperature for

Fe based biochars had signifjcant efgect.

1 2 3 4 5 20 40 60 80 100 P-Fe-700 P-Fe-500 HTC-Fe Reaction Time (h) MB removal (%)

RESUL TS- FeSO4 based catalyst

0,5 1 1,5 2 2,5 3 3,5 20 40 60 80 100 P-Fe-700 P-Fe-500 HTC-Fe Reaction Time (h) MB removal (%)

20 hours !!!

Day light Under Dark

0.5 1 2 3 4 5 7 16 20 20 40 60 80 100

P-Fe-700

Reaction Time (h) MB removal, %

Fe content of effmuent water, ppb P-Fe-500 128 P-Fe-700 4 HTC-Fe 357

RESUL TS- Cyclic usage of catalyst

Conditions: 50 ppm MB, 10 mM H2O2, daylight, 150 rpm shaker, no pH adjustment ( ~3.5)

1st 2nd 3rd 4th 5th 10 20 30 40 50 60 70 80 90 100 P-Fe-500 HTC-Fe Cycle MB removal, %

• No activity losses in

case of P-Fe-500 after 5 cycle.

Fenton oxidation with P-Fe-500

Before After

RESUL TS- FeSO4 based catalyst

Inorganic content, %

P-Fe-500 P-Fe-700 HTC-Fe Fe 22.02 25.86 1.35 Al 0.06 0.07 0.07 Si

• 0.02

0.03 Mg 0.09 0.11

• Na

0.29 0.32 0.12 Ca 0.27 0.32 0.09 K 3.22 4.01 0.11

• Loading of Fe failed by

hydrothermal carbonization HTC-Fe

SEM images

P-Fe-500 P-Fe-700

Iron particles

RESUL TS- FeSO4 based catalyst

XRD pattern FTIR spectrum

5 15 25 35 45 55 65 75 85 P-Fe- 500 2 Theta In te n s ity

✮ ✮

5 15 25 35 45 55 65 75 85

HTC-Fe

2 Theta Intensity 650 1150 1650 2150 2650 3150 3650 P-Fe-500 HTC-Fe Wavenumber (cm-1)

• OH

Aliphatic -CH3 Carboxylic C=O Aliphatic C-O-C Aromatic C=C

✮Fe3O4 ▲Fe2O3 ✮ ✮ ▲

1 2 3 4 5 6 7 10 20 30 40 50 60 70 80 90 100 50 ppm 100 ppm 150 ppm 200 ppm Reaction time (h) MB Removal, %

RESUL TS- Parametric study

Conditions: 10 mM H2O2, daylight, 150 rpm shaker, no pH adjustment ( ~3.5)

Catalyst: P-Fe-500

MB concentration: 50, 100, 150 and 200 ppm Concentration Removal

RESUL TS- Parametric study

Conditions: 50 ppm MB, daylight, 150 rpm shaker, no pH adjustment ( ~3.5)

Catalyst: P-Fe-500

Initial H2O2 concentration: 2.5, 5, 10 and 15 m M

1 2 3 4 5 6 7 10 20 30 40 50 60 70 80 90 100 2.5 mM 5 mM 10 mM 15 Reaction time (h) MB Removal( %)

Lower H2O2 concentration longer reaction time

1 2 3 4 5 6 7 10 20 30 40 50 60 70 80 90 100 2.6 3.8 7 9 Reaction time (h) MB Removal, %

RESUL TS- Parametric study

Conditions: 50 ppm MB, 10mM H2O2 concentration, daylight, 150 rpm shaker,

Catalyst: P-Fe-500

pH: 2.5, 3.6 (natural pH of MB), 7 and 9 After 24 h removal was not completed!! Low pH increases solubility of Fe ions

Conclusion

 Ongoing studies focus on red mud to produce efgective and stable catalyst, independent from difgerent pH.  In future work, difgerent pollutants can be tested in their natural pH.

• Fenton oxidation of MB was achieved with the catalysts prepared by

TP .

• Release of Fe faciliates degradation of MB.
• P-Fe-500 had the highest activity stability in 5 cycles. Fe

concentration in effmuent water is acceptable for direct dumping.

• pH is most efgective parameter, which afgect the solubility of Fe in

wastewater.

• Biochars obtained by pyrolysis showed magnetic properties whereas

magnetic biochar could not produced by HTC.

• Biochar obtained from pyrolysis at lower temperature showed higher

activity than that at higher temperatures.

Special Thanks…

• PhD candidate Gulen T

ekin

• Dr. Dogan T

ac

• Dr. Raif Ilkac
• Berkay Leskeri

THANK YOU FOR LISTENING…